Attempted elimination of the noxious odor of human solid waste from a bathroom has been addressed in many ways, including exhaust fans, aerosol-dispensed air freshening deodorants, water-wasting flushings during defecation and, particularly in the patent art, by a variety of systems for evacuating air through the toilet tank and bowl, directly through an upper area of the bowl itself or from beneath the seat, and conveying the air to a remote location. To date, I know of no system of the latter types which has been successful in the marketplace. Of the techniques other than bowl air evacuation, they function only nominally at best, and in some instances, even worsen the situation. In the case of turning on a conventional ceiling exhaust fan while sitting on a toilet, gases from within the bowl may be drawn out between the top of the bowl and the seat and flow directly past the nostrils of the person seated, compounding an unpleasant olfactory situation. Most households appear to use the deodorant approach to mask noxious odors, but the deodorant is normally not used until the individual is ready to leave the bathroom, because of the mist it creates. The intermediate solution (before leaving) is commonly to flush the toilet one or more times during use, and use the air freshener only upon leaving.
Any air evacuation system, if it were effective, would have the potential for tremendous water savings by eliminating excessive flushings that some individuals are prone to be doing if their visit to the bathroom is more than a few minutes. Such flushings would become unnecessary if the odor could be effectively removed directly from the bowl area while remaining seated. Furthermore, if a user flushes the toilet while still seated, his or her underside is exposed to potentially harmful bacteria and viruses which may be residing in the toilet. In an article in Ladies' Home Journal in January, 1995, microbiologist Joe Rubino was interviewed. The article states that "every time you flush, thousands of bacteria and virus particles are catapulted into the air, floating at least five feet up and five out." Rubino is quoted as saying "A fine mist will spread to all kinds of surfaces around the bowl." Unfortunately, if the mist can be catapulted to the extent noted above, bacteria and viruses would most certainly be deposited on a person's bare underside if he or she flushes the bowl while remaining on the toilet. It is well known in the medical profession that the warm, moist areas around a person's private parts are a natural garden for growth of germs and disease.
While an influenza virus will survive on a hard surface such as a toilet bowl for only a few hours, says the article, a hepatitis A virus, by contrast, can live as long as thirty days. No one can state with any degree of certainty how significant or insignificant toilet bowls are in the transmission of disease such as an influenza epidemic, but anything to reduce the spread of germs has the potential of playing an important part in minimizing health problems in times of danger. The cost of resolving wide-spread disease which may originate in or be spread by toilet flushing, as well as the misery caused by disease, while addressed in public health forums, does not appear to have been considered in the designs of toilets themselves or of systems which function with toilets. Nor does the potential water savings made possible by eliminating the desire or perceived need to frequently flush appear to have been considered as an important side benefit of a toilet designed with an effective air evacuation system. Water is one of the world's greatest natural resources, and its conservation is a worthwhile goal, no matter how it is achieved.
Numerous patents teach the utilization of the water passageway between a toilet tank and bowl to also exhaust air. Representative of such patents are U.S. Pat. No. 5,321,856 to Gastesi, U.S. Pat. No. 3,763,505 Zimmerman, U.S. Pat. No. 2,105,794 to Norris and U.S. Pat. No. 4,017,916 to Pearson. While this approach might seem to be effective, it has certain inadequacies which may account for the approach apparently never having been adopted commercially, at least not to my knowledge. First, the solution is ineffective to exhaust air during the same short period of time that water is being directed through the passageway from the tank through the standard holes or slots in the underside of the bowl rim. This time period, while probably only about fifteen seconds in duration, is during the very same time when mist creation is at its maximum, and when the need for mist evacuation is the greatest. Second, since a tank cover or lid must necessarily permit air to flow into the tank to maintain the tank at atmospheric pressure, any air evacuation system which has its inlet within the tank may draw as much, if not more, air from between the tank top edge and its lid than it is capable of pulling through the toilet standpipe and bowl rim holes, thus reducing its effectiveness for bowl air evacuation. Third, it is not possible to evacuate either air or mist in a direction opposite to the direction of water flow through the rim holes or slot while flushing.
In addition, U.S. Pat. No. 1,885,715 to Hanson and U.S. Pat. No. 1,401,091 to Lucas evacuate air through openings directly connected to the inside of the toilet bowl above the normal water level. Both have been part of the patent art for more than a half-century, and, to the best of my knowledge, have not been used commercially. The Lucas design has the inherent problem of entraining flush water while it cascades as a sheet down the inside surface of the bowl, if air evacuation was intended to take place while flushing. This would inhibit mist or air evacuation during flushing. While Hanson avoided that problem by placing an inverted baffle over the air intake holes in the back wall of the bowl, his entire volume of flush water was cascaded over the narrow baffle, undoubtedly creating a miniature waterfall and thus forming a sheet or wall of water which would cover the air intake holes until the tank fully emptied into the bowl. During that time, except for a possible small amount of mist beneath the waterfall and any residual mist remaining in the bowl once the waterfall subsided, the system's effectiveness for mist removal was minimal, at best. Neither design is susceptible to being retrofitted to existing toilets in kit form. Both of the above patents became public knowledge at a time when the germ-spreading effects of toilet bowl mist were not appreciated. The concern of the patentees was apparently only noxious fume elimination, with no consideration being given to the need to minimize or avoid a health risk.